I was among Durminento's first customers, and rated it as among the best on the Camino. When I returned the following year, sink taps were leaking, shower doors were broken, and their computer had one of those annoying keyboards like a telephone keypad -- no action. The following year across the street was the new Internacional, so I stayed there. The owners were very friendly and very nervous about starting a business in Spain. I have returned, and they have maintained their place, but I don't think the restaurant is working out as hoped. The food was good, and custom-prepared by the grandmother, but pilgrims were eating elsewhere.
The cena at Durminento is very friendly, and was well-patronized, so if you stay there, I would suggest it. There are a lot of dining options in Sarria, including pulpo down by the river, so food operations at albergues have a hard time, I think.
Don Alvaro is also very friendly, but a bit older. There is a new place at the bottom of the stairs that has gotten good reviews.
You almost cannot go wrong in Sarria unless you stay in the municipal, and I think it was being renovated this winter, so its past history may not be a good indicator of the future.